My car has been sitting for about 3 years since its run gas from its own tank. From what the previous owner tells me, the tank is about half full of old 85 octane. What do you think I should do? Replace the whole system from straps to engine? The engine was rebuilt then run off a different gas source so this old gas has not gone into the engine or carb. I was thinking about replacing it ALL. Tank, sender, filter, lines, even straps just to be safe (and upgrade to some steel lines). What ya think?

 

There is no reason to replace the gas tank and sender. You might want to take the tank out of the car and recondition it with a kit from Summit, Kanter, etc. Definitely replace the filter.

 

So then maybe just upgrade the lines?

 

If you think or suspect that the lines are damaged or are rusty then yes. You may be able to attach an electric pump (fairly cheap) on the end of the lines where the tank would be running to a jerry can of new fuel and pump that through the lines up to the mechanical pump. Disconnect the line at the inlet of the mechanical pump and then observe what comes out, especially in the first few moments. If the fuel is clean with no tinge of red or rust then you probably don't have any worries. Since you will be under the vehicle to remove the tank and clean it out do a thorough inspection of the lines for kinks and crimps too, probably before you flush them. I had to r/r the fuel lines and the brake lines on my '46 project and it isn't an easy task, measure, bend and fit, measure, bend and fit, all the while having sixty year old dirt and crap falling all over you.